The population explosion problem is particularly acute in many underdeveloped countries of the world. The governments of many of these countries seek to solve the population explosion problem by offering voluntary sterilization services to its adult citizens through various government sponsored incentives and programs. Surgical methods of sterilization have proved to be unsatisfactory primarily for four reasons: surgical techniques are relatively expensive; surgery often forces the patient to stay away from home at a hospital or health care facility; surgery can be painful when performed on an out patient basis; and rare, adverse reactions to surgery cause the citizens to become superstitious and fearful of surgery. Consequently, efforts have intensified over the last twenty years to use transcervical techniques to achieve sterilization by occlusion of the oviducts. Although transcervical techniques have been used for at least one hundred years, they still do not achieve sterilization in a relatively large percent of women.
The use of various toxic chemicals such as quinacrine, to achieve oviduct occlusion has been reviewed in a recent article by R. M. Richard in "Research Frontiers In Fertility Regulation", Vol. I, No. 5 (December 1981) and in a book entitled "Female Transcervical Sterilization" edited by Zatuchni, Shelton, Goldsmith, and Sciarra and published by Harper & Row. All of the methods described are based on the principle that the fluid damages the oviducts and the subsequent healing processes occlude the oviducts. Experiments performed by the inventor and others indicate that non-penetration of the toxic fluid into the oviducts is at least one of the reasons that chemicals such as quinacrine fail to occlude the oviducts in a large number of cases. Also, further experiments performed by the inventor and others indicate that such non-penetration is attributable to adhesive forces that hold the oviduct folds together or to spasm of the muscles of the uterus surrounding the oviducts. A relatively high rate of oviduct occlusion has been achieved by multiple injections of a toxic fluid into the uterine cavity and by injecting the toxic fluids into the intrauterine cavity under pressure. The procedure of multiple injections suffers from the drawback that the patient must visit a doctor or clinic on several occasions. The procedure of pressurizing the toxic fluid suffers from two major drawbacks. First, this procedure uses excessive amounts of the toxic fluid, which sometimes causes the fluid to flow through one or both fallopian tubes into the peritoneal cavity, which in turn can damage the peritoneal cavity or cause the toxic fluid to be injected into the blood stream. Second, this procedure sometimes causes one fallopian tube to open before the other fallopian tube, thereby reducing the intrauterine pressure and making it difficult for the other fallopian tube to open.
The present invention was developed primarily in an effort to find a quick, inexpensive, safe and highly successful transcervical technique of oviduct occlusion by injecting toxic fluids into the intrauterine cavity and the fallopian tubes.